The National Assembly on Thursday passed a resolution condemning China’s retaliation against the deployment of a US missile shield system here. Five political parties, including the far-left Justice Party, supported the resolution.

Such a resolution is long overdue and its adoption should become an occasion to start speaking up against the Beijing government, which has been acting like a bully.

One good aspect of the parliamentary resolution is that it embraced liberal groups such as the Democratic Party of Korea and the People’s Party, which still oppose the stationing of the Terminal High Altitude Area Defense battery in South Korea.

That should send a clear message to China that major parties, regardless of their respective positions on the THAAD deployment itself, are united against what China has been doing since Seoul and Washington decided to bring the anti-missile system here to deter North Korea’s nuclear and missile threats.

The National Assembly resolution is also significant in that South Korea has taken few official actions while China has ratcheted up its punitive measures over the past several months.

The leadership vacuum caused by the impeachment of Park Geun-hye and the early presidential election might have stood in the way of Korea taking adequate countermeasures.

Nevertheless, political leaders cannot avoid criticism that they have kept too low a profile on the issue, which has been impacting an increasing number of industries and businesses. Acting President Hwang Kyo-ahn has spoken about the issue, but none of his statements were addressed to Chinese leaders.

We have also not heard our foreign minister publicly criticize the Chinese government. It was only on Tuesday that Kim Jang-soo, ambassador to China, officially asked the Chinese government to allow Lotte to resume business of its supermarkets that had been suspended.

Before that, the Seoul government’s only official action -- asking the World Trade Organization to look into the issue -- came last week, after a long delay. There is a strong possibility that the Chinese government will not admit any government role in the retaliatory measures. It is the Seoul government’s job to provide evidence that the Chinese measures -- especially the ban on tour and cultural programs and repression of retail and import businesses -- violate WTO regulations.

A bipartisan resolution passed Thursday by the US House Foreign Affairs Committee regarding North Korean threat also pointed out that “China’s retaliatory measures against South Korea potentially constitutes a violation of its World Trade Organization obligations.”

“The House of Representatives urges the Government of the People’s Republic of China to immediately cease its diplomatic intimidation and economic coercion against South Korea in an attempt to block the THAAD deployment,” the resolution said.

US officials said Secretary of State Rex Tillerson delivered Washington’s concern about the Chinese measures against South Korea during his recent meetings in Beijing with Chinese leaders.

“The secretary conveyed it very strongly to the Chinese side and the secretary also said in private meetings that really retaliating against a defensive system which China has done was something that was uncalled for and something of a growing concern for us,” said Joseph Yun, the US nuclear envoy who visited the region recently.

US Defense Secretary James Mattis also lashed out at China last week for taking a “tribute nation” approach to other countries and seeking “veto power” over sovereign decisions made by neighboring nations.

The series of remarks by senior US officials is assuring in that they came in the run-up to a summit between US President Donald Trump and Chinese President Xi Jinping in Washington next month.

Trump may well exercise his usual straightforwardness and speak up to urge Xi to look at the issue squarely and realize that China’s job is not to sanction South Korea but to pressure North Korea to give up its nuclear and missile provocations.